Fluid motor mechanism



Oct. 26, 1943.

.1. c. MCCUNE 2,332,585

FLUID MOTOR MECHANISM Filed I Oct 51, 1941 Fig.2. 1 152541 A a 20 l V 7 v I8 I lq% 6 F' .5 I3 I .34 a? a; 34 az 30 H.

INVENTOR Joseph GMcCun e Y ATTOJR N EY Patented Oct. 26, 1943 STATES PATENT FLUin o roR MECHANISM I Mciinneliidgewo ii d l :issignor to I twhegwest i'nehause Air Br'ali C nie'rtlin'g, Pa, ach'rporation of Rnnsyl'ya ia v Application October at, 1 941;stsh'm ahmss I i r echhhns.v (Cl. s u tii i. This. ihizention ieiateg t6 iiiiidjmth m eha V nifsr'ii'ahii mare particiilarlii to rih, type-brake cylihd'ii devices such as iflsed in connection with disk t pe of brake niecha'ifiisin.

device isusiiall'y cefiilected ci irect ly to the hrakint; Hisiis in turn are generally associated directly with thehernber to be braked When su'ch a fiiechahishifis therefore hppl iedta' railway vehicl'sQthe brake cylinder device along with the iiisks are mere or less-intimately associated with, the wheels and ax les to e. braked and siibj'ct directly to gut, moisture and otl'l'ei'v foreign matter incident to such a location! The efitr'a'nfi (if ibre'ign niatterfinto the brake" funde'sira-hle on account of wear or ras fhay resuittherefro n. The

v ifi n i t er f e i 4 i. the tree" on foreign ihatter therefrom s V V k I editing type. fluid m0 tor mechanism embodying means for excluding other bhjects'a'nd advan age will be appa en j from the reu w'ihgmbre detailed description of the' ifiviiti'dnf i n the'accornpanyi'ng drawihg, Fig. 1' is an end view partly in section er a, portion of a disk brake, mechanism embodying a ring type, brake cylir'ider device. 'constructed in. accordance with one A form. of the inventionfth'e"sectionatpart being A taken on line [-4 'i'nFigL '2; Fi'gfz is a sectional shaped piston bore-2 having inner and outerconcentric and.cylindricalrcylinder Walls or surfaces 3 and 4, respectively. These walls are joined,v at.

one end to a radial wall "5 which constitutes the pressure end. ofthe borer The. opp'ositeend of the piston bore is open through the end of the casing.

A vhin shaped brake; cylinder piston t is: 51m: On the inner end ably mounted in the bore 2. of :piston B is a. flexible-packing cup I which cowail t. v zen-expansion scraper ring '2 [is mountejdin the operates with the end wall 5: of the piston bore to c form a pressure chamber 8i to which fluid under pressure is adapted to be supplied for effecting relative parting movement. between. the piston (5 i,

and easing I for applying-brakes.

, Release-pf 1 fluid: under pressure-from the chamber 8 isadapt- 1 ed to provide -;for relative movement: betweenrthe; '55

whileth'e: other part;

piston and casing in the e'ppete fiietion-,i. e., telescoping mov'er neht toproi icie-ror a release of brakes.- Either the easin -l or piston 2 may be the statienarry part or" the brake cylinder device 1 be the part capable of" above described. This relative. movement,

howeveh is immaterial s0- iar the invention is concerned, aswinheappereht. f j A'c'c'o'rdi'ng it) this er hoehhe tzor thein ven tion; the iston 6 'cempr'i'ses afriniierannular part in "engaging the packing cup 1 and an out-eh annular part HI having en aging theact jac'ent'e'r'id e f the part in. Theopp'esite en on the outer part enigaged by a member 12: a

cylinder device er a braking pressure transmit: tin=gmembenmovab1e by thebrake e iihder p ten h. One or more Screws I13 extendthroughsuitably aligned bores; the 12 am annular art- I 0 T531 rigid-3y securing iid member and two parts together, With the brake cyiin may-constitute either a: shpperh for the-brake .anhuiahpart Hints a-serewthreaa'es borem the der pi'st'on ih-its brake-release pesitioh shown; the

member. {2 suhstantiaiiy engages the casing around the'o'pen en'd'or bore 2;

Theinnerand; outer parts it a fid n er the brake-cy1inder piston have respectively, ihh' i,-

axially. aligned,h hnerica hearing surfaces 1 4 arhiilahavin substahtiaiishuihg cia'iitac't with thecylindrical surfaces Hi and H iormedht adi ameter less than-that of the enter eyliheer Wail 4 in.'ord'e1't:t'o provide a space ohehember ifl-ior" receiving mreighnmetter without Such foreign matter being-forced into-contact with the ct -lin der: Wall 4-.

The outerfsurface W entire inner paw m 5 as at she side'of ring groove the piston term" 7 l9; the opposite hire or which 'isfar ed y n annular" part- 20 of thepi'steh' which bears" against and supperts thee-eel: or the pecking cup groove f9 and bears against the outer cylinder wall "[4. The enter surface IT of the pist's part lo being of the diameter above mentioned, ra'cnh tates'the application of'r'ing 2;! to the groove f9,

without breaking same.

Uponparting rhqve'meut h the piston s and casing the-ring 2-lis adapt-ed to scrape foreign f tapered away from the cylinder wall 4 in the direction of the packing cup I, and the purpose of this is to allow thering to move or slide over any foreign matter which may be on the cylinder 7 wall 4 upon telescopic movement of the piston and cylinder. By this arrangement the cylinder wall 4 on the side of the ring 2| adjacent the packing cup I will at all times be maintained as free as possible of foreign matter so as to mini mize wear.

The inner cylinder wall 3 is shorter than the.

outer cylinder wall 4 in that it terminates at' the inner side wall 23 of a ring groove 24 in the casing. The outer side wall of the groove 24 is formed in an annular extension 25 of the cas ing; which is engaged by the memberQJZ with the piston 6 in release position. The inner peripheral surface 2% of extension 25 is formed at aless diameter than the inner cylinder wall 3 in order expansion ring to facilitate the mounting of an 21 in the ring groove 24.

It will be noted that-ring 27 is disposed in e casing while ring 2| is mounted in the piston;

and this is desirable in order to avoid unneces sary weakening of the piston'as would resultif' a second ring groove were provided in the piston to open at the inner surface'of. the piston.

Upon telescopic movement of piston 6 and cas ing 2 it will be apparent that the ring 21 engaging the inner surface of'the piston will remove foreign matter therefrom and 'thus prevent its entrance into the cylinder where it wouldtend to cause unduewear.

The surface of ring. 21

engaging the piston is tapered like that of ring 2|.so that upon parting movement ofythe piston and casing, the ring 2! will tend to ride over any foreign matter which may be present on the inner piston surfaces l5, and; M; After such riding over foreign matter by both scraper rings 2| and 2'! it will beseen that upon subsequent relative movement between the partsin-the opposite direction said rings will tend to remove said foreign matter from the surfaces in sliding con-'1 tact with the rings and thus prevent entry thereofa.

to the interior of the brake cylinder device,v

vThe member l2 closing the-open end "of the pistonbore with the piston 6 in its releaserpos'ition acts to prevent the entranceof foreign mat,- 2

ter intothe open end of piston bore 2, and'since this is the position said member will occupy the greater portion of the timethe device isin use, p

the, amount'of foreign matter which maybe ob tained in the piston bore to be removed by the scraper rin s 2i and 2'! and thereby excluded from the packing cup I will not be great.* J 4 The length of the inner annular part 10 of the piston is such that with the piston in its release position shown, said'part. will not overlap the scraper ring groovev24. Adjacent the outer ends of the cylinder walls 3 and 4 there are provided,

outwardly flaring Wall parts 28 and 29; respectively. The inner surface IE on the outer part ll of the piston is joined at its inner endto a beveled surface 30 which is tapered inwardly in the direction of the inner part [0, these details of structure being essential to facilitate mounting} of the piston 6 in the piston bore 2,'which now be described.

To-assemble the piston 6 in bore Z, the screw I3 must be removed for separating. the piston parts l6 and H and the member! 2. Also the scraper ring 21 must be removed from the groove.

24 The ringJZI and packing cup 1 are then applied to the piston part I!) and this assembly:

is mounted in ther pistonsbore to the'position bore is slidably mounte clearly illustrate the inventionf 'lheseficl'ear'arice outer concentrically arrangedicylinder surfaces;

shown in the drawing in which no part of the ring groove 24 is covered by the piston part III. The tapered surfaces 28 and 29 at'the open end of the piston bore are adapted to compress the leading edges of the packing cup I and also the scraper ring 2] to facilitate mounting of these parts in the piston bore 2. v

The scraper ring 21' is next, expanded over surface 26 on the casing and slipped tothe groove 24 into which it contracts? The outer part II, of the piston is then mounted over the scraper ring 21 which compresses said ring to its working 'positionhthetapered surface IS on said part facilitating this operation. Then the member l2-ismounted against the outer part II of the pistonandthegscrew1 [3 applied for securing the -two""parts"of 'the" piston together and to said member...:

" DescriptionFig. 3

Inthe embodiment shown in Fig.13lthe brake cylinder casing has 7 a piston boljqwithinnerand. er concentrically. arrao gcvl ndrisfa eyl de Wal1s 30" ar1d 3| of the same length, and'injtlils f oneeplecegbrake cylinder piston 32 which l3 to member l2. *The'pis'ton;3 2 has inner and outer cylindrical bearing" surfaces 33 and 134, spectively, arranged in concentric relationfw the cylinder-walls '30and" 31, The pistonis such length that in its release position it projects slightly beyond the open end of the piston bpre In the drawing relative great-clearancei's sho between the piston surfaces, 33*and1 34 and th adjacent cylinder walls 3| 'and"'33 infor 'dent however need bepo. different} from normal an in practice might be' the same as would be" e ployedin onwimeiwithjt m im nt i Figs, 1 a fi 'ee cri e r. A contracting scraper'f ringfl'35.'is "teri one around the piston 32 in contactwith thebearing' surface-34 and is disposed-in a recessgpi ovid d in the end of the casing." This 'ringji s heldj place by a retaining member flj securedj by' a",-' I screw Sl to the casing. An expanding scrapers. j ring 38 is disposedinalrecegsj infthe'partof the casing encircled 'by the piston for sliding contac with the inner bearing surface"33 of'the piston and this ring is held "in" place;by; a retainin' mernber 39 secured to the fcasingib'y screw: 40

The two scraper rings. 35g.and3a ara'preferab y of metal and relatively thin toproviderelatively .narrow bearing contacts'vvith'thefouter and ner surfaces 34 and 33 ofhthe piston so as. to

minimize the possibility of foreign matter wedging itself past said. rings; r In operation it will .be apparent that the scrapa;

ing action-0f rings 35;and' '38. on the two bearing surfaces 33 and 34. of thepiston 32- upon tele-fl scoping of the piston and easing vvill 'acttoremove foreign :matter from said surfaces before 13 and the other part constituting an: annular" piston mounted in said bore between-said surfaces- 3 u eated b nsc ewz l and having inner and outer surfaces in concentric relation with said cylinder surfaces, two expansive scraper rings, one encircling and the other encircled by said piston, each of said rings having a rigid scraping edge and being secured to one of said parts with its scraping edge in scraping contact with the adjacent said inner or outer surface of the said other part, both of said rings being operative upon relative movement between said two parts to block passage of foreign matter past said rings in the direction of said closed end of said bore.

2. A fluid motor mechanism comprising in combination, two telescopically associated parts, one of said parts constituting a casing having an annular piston bore closed at one end and open at the opposite end, said bore having inner and outer concentrically arranged cylinder surfaces, and the other part constituting an annular piston mounted in said bore between said surfaces and having inner and outer surfaces in concentric relation with said cylinder surfaces, two scraper rings, one encircling and the other encircled by said piston, each of said rings being secured to one of said parts and having scraping contact with the adjacent said inner or outer surface of the said other part, both of said rings being so designed and arranged as to scrape foreign matter from the surfaces engaged upon relative movement between the parts which would tend to carry foreign matter into the spaces between said rings and the closed end of said bore and to slide over foreign matter on said surfaces upon relative movement in the reverse direction.

3. A fluid motor mechanism comprising in combination, two telescopically associated parts, one of said parts constituting a casing having an annular piston bore closed at one end and open at the opposite end, said bore having inner and outer concentrically arranged cylinder surfaces, and the other part constituting an annular piston mounted in said bore between said surfaces and having inner and outer surfaces in concentric relation with said cylinder surfaces, a scraper ring carried in said piston and tensioned into scraping contact with said outer surface of said bore, a scraper ring carried by said casing and tensioned into scraping contact with said inner surface of said piston, said rings being operative upon relative movement between said two parts to scrape foreign matter from the contacted surfaces and thereby block passage of same into the spaces between said rings and the closed end of said bore. I

4. A fluid motor mechanism comprising in combination, two telescopically associated parts, one of said'parts constituting a casing having an annular piston bore closed at one end and open at the opposite end, said bore having inner and outer concentrically arranged cylinder surfaces, and the other part constituting an annular piston mounted in said bore between said surfaces and having inner and outer surfaces in concentric relation with said cylinder surfaces, a scraper ring carried by and extending through one of said surfaces of said piston and tensioned into scraping contact with the adjacent surface of: said the piston ring groove.

two parts to scrape foreign matter from the contacted surfaces for preventing passage of such foreign matter into the spaces between said rings and the closed end of said bore, the peripheries of said rings in scraping contact with the respective surfaces of said casing and piston being tapered to ride over foreignmatter on such surfaces upon relative movement between said two parts opposite that in which said rings scrape foreign matterfrom such surfaces.

5. A fluid motor mechanism comprising in combination, two telescopically associated parts, one of said parts constituting a casing having an annular piston bore closed at one end and open at the opposite end, said bore having inner and outer concentrically arranged cylinder walls, and the other part constituting an annular piston mounted in said bore between said walls and having inner and outer surfaces arranged in concentric relation with saidwalls, said casing having at the open end a radially extending ring groove opening at the outer end of one of said walls, said piston comprising an inner part adapted to be positioned toward the closed end of said bore beyond said groove, said inner part of said pistonliaving at the end adjacent the closed end of said bore a radially extending ring groove open to the surface thereof adjacent the other cylinder wall, a scraper ring in the last named ring groove tensioned radially into scrap ing contact with the said other cylinder wall, said piston comprising an annular outer part, means removably securing said outer part to said inner part, and ascraper ring in the ring groove in said casing tensioned radially into contact with the adjacent piston surface.

6. A fluid motor mechanism comprising in combination, two telescopically associated parts, one of said parts constituting a casing having an annular piston bore closed at one end and open at the opposite end, said bore having inner and outer concentrically arranged cylinder walls, and the other part constituting an annular piston mounted in said bore between said walls and havinginner and outer surfaces arranged in concentric relation with said walls, said casing having at the open end a radially extending ring groove openingat the outer end of one of said walls, said piston comprising an inner part adapted to be positioned toward the closed end of said bore beyond said groove, said inner part of said piston having at the end adjacent the closed end of said bore a radially extending ring groove open to the surface thereof adjacent the other cylinder wall, a scraper ring in the last named ring groove tensioned radially into scraping contact with the said other cylinder wall, said piston comprising an annular outer part, means removably securing said outer part to said inner part, and a scraper ring in the ring groove in said casing tensioned radially into contact with the adjacent piston surface, the surface of said inner part of said piston at the side of the ring therein adjacent the closed end of said bore being of substantially the same diameter as the adjacent cylinder wall'but at the opposite side of said ring of a different diameter to provide a space therebetween and the adjacent cylinder wall and to facilitate mounting the piston ring in JOSEPH C. MCGUIIE. 

